refactor(peer-exchange): move peer management to waku_node module

apps/wakunode2/wakunode2.nim

@@ -433,7 +433,7 @@ proc setupProtocols(node: WakuNode, conf: WakuNodeConf,
   # waku peer exchange setup
   if (conf.peerExchangeNode != "") or (conf.peerExchange):
     try:
-      await mountWakuPeerExchange(node)
+      await mountPeerExchange(node)
     except:
       return err("failed to mount waku peer-exchange protocol: " & getCurrentExceptionMsg())
 

tests/v2/test_waku_peer_exchange.nim

@@ -124,14 +124,14 @@ procSuite "Waku Peer Exchange":
     await allFutures([node1.startDiscv5(), node2.startDiscv5()])
 
     # Mount peer exchange
-    await node1.mountWakuPeerExchange()
-    await node3.mountWakuPeerExchange()
+    await node1.mountPeerExchange()
+    await node3.mountPeerExchange()
 
     await sleepAsync(3000.millis) # Give the algorithm some time to work its magic
 
     asyncSpawn node1.wakuPeerExchange.runPeerExchangeDiscv5Loop()
 
-    node3.wakuPeerExchange.setPeer(node1.switch.peerInfo.toRemotePeerInfo())
+    node3.setPeerExchangePeer(node1.peerInfo.toRemotePeerInfo())
 
     ## When
     discard waitFor node3.wakuPeerExchange.request(1)

waku/v2/node/waku_node.nim

@@ -41,6 +41,7 @@ declarePublicGauge waku_node_filters, "number of content filter subscriptions"
 declarePublicGauge waku_node_errors, "number of wakunode errors", ["type"]
 declarePublicGauge waku_lightpush_peers, "number of lightpush peers"
 declarePublicGauge waku_store_peers, "number of store peers"
+declarePublicGauge waku_px_peers, "number of peers (in the node's peerManager) supporting the peer exchange protocol"
 
 
 logScope:
@@ -697,20 +698,21 @@ proc lightpushPublish*(node: WakuNode, pubsubTopic: PubsubTopic, message: WakuMe
 
 ## Waku peer-exchange
 
-proc mountWakuPeerExchange*(node: WakuNode) {.async, raises: [Defect, LPError].} =
+proc mountPeerExchange*(node: WakuNode) {.async, raises: [Defect, LPError].} =
   info "mounting waku peer exchange"
 
   var discv5Opt: Option[WakuDiscoveryV5]
   if not node.wakuDiscV5.isNil():
     discv5Opt = some(node.wakuDiscV5)
-  node.wakuPeerExchange = WakuPeerExchange.init(node.peerManager, discv5Opt)
+
+  node.wakuPeerExchange = WakuPeerExchange.new(node.peerManager, discv5Opt)
 
   if node.started:
-    # Node has started already. Let's start Waku peer exchange too.
     await node.wakuPeerExchange.start()
 
   node.switch.mount(node.wakuPeerExchange, protocolMatcher(WakuPeerExchangeCodec))
 
+# TODO: Move to application module (e.g., wakunode2.nim)
 proc setPeerExchangePeer*(node: WakuNode, peer: RemotePeerInfo|string) {.raises: [Defect, ValueError, LPError].} =
   if node.wakuPeerExchange.isNil():
     error "could not set peer, waku peer-exchange is nil"
@@ -720,7 +722,8 @@ proc setPeerExchangePeer*(node: WakuNode, peer: RemotePeerInfo|string) {.raises:
 
   let remotePeer = when peer is string: parseRemotePeerInfo(peer)
                    else: peer
-  node.wakuPeerExchange.setPeer(remotePeer)
+  node.peerManager.addPeer(remotePeer, WakuPeerExchangeCodec)
+  waku_px_peers.inc()
 
 
 ## Other protocols

waku/v2/protocol/waku_peer_exchange.nim

@@ -3,11 +3,8 @@
 import
   ./waku_peer_exchange/rpc,
   ./waku_peer_exchange/rpc_codec,
-  ./waku_peer_exchange/protocol,
-  ./waku_peer_exchange/client
-
+  ./waku_peer_exchange/protocol
 export
   rpc,
   rpc_codec,
-  protocol,
-  client
+  protocol

waku/v2/protocol/waku_peer_exchange/client.nim

@@ -1,9 +0,0 @@
-{.push raises: [Defect].}
-
-import 
-  std/[tables, sequtils],
-  chronicles
-import
-  ../waku_message,
-  ./rpc
-

waku/v2/protocol/waku_peer_exchange/protocol.nim

@@ -17,7 +17,6 @@ import
   ./rpc_codec
 
 
-declarePublicGauge waku_px_peers, "number of peers (in the node's peerManager) supporting the peer exchange protocol"
 declarePublicGauge waku_px_peers_received_total, "number of ENRs received via peer exchange"
 declarePublicGauge waku_px_peers_received_unknown, "number of previously unknown ENRs received via peer exchange"
 declarePublicGauge waku_px_peers_sent, "number of ENRs sent to peer exchange requesters"
@@ -107,7 +106,7 @@ proc respond(wpx: WakuPeerExchange, enrs: seq[enr.Record], peer: RemotePeerInfo
 
   return ok()
 
-proc respond*(wpx: WakuPeerExchange, enrs: seq[enr.Record]): Future[WakuPeerExchangeResult[void]] {.async, gcsafe.} =
+proc respond(wpx: WakuPeerExchange, enrs: seq[enr.Record]): Future[WakuPeerExchangeResult[void]] {.async, gcsafe.} =
   let peerOpt = wpx.peerManager.selectPeer(WakuPeerExchangeCodec)
   if peerOpt.isNone():
     waku_px_errors.inc(labelValues = [peerNotFoundFailure])
@@ -115,48 +114,47 @@ proc respond*(wpx: WakuPeerExchange, enrs: seq[enr.Record]): Future[WakuPeerExch
 
   return await wpx.respond(enrs, peerOpt.get())
 
-proc cleanCache(px: WakuPeerExchange) {.gcsafe.} =
-  px.enrCache.delete(0, CacheCleanWindow-1)
+proc cleanCache(wpx: WakuPeerExchange) {.gcsafe.} =
+  wpx.enrCache.delete(0..CacheCleanWindow-1)
 
-proc runPeerExchangeDiscv5Loop*(px: WakuPeerExchange) {.async, gcsafe.} =
+proc runPeerExchangeDiscv5Loop*(wpx: WakuPeerExchange) {.async, gcsafe.} =
   ## Runs a discv5 loop adding new peers to the px peer cache
-  if px.wakuDiscv5.isNone():
+  if wpx.wakuDiscv5.isNone():
     warn "Trying to run discovery v5 (for PX) while it's disabled"
     return
 
   info "Starting peer exchange discovery v5 loop"
 
-  while px.wakuDiscv5.get().listening:
+  while wpx.wakuDiscv5.get().listening:
     trace "Running px discv5 discovery loop"
-    let discoveredPeers = await px.wakuDiscv5.get().findRandomPeers()
+    let discoveredPeers = await wpx.wakuDiscv5.get().findRandomPeers()
     info "Discovered px peers via discv5", count=discoveredPeers.get().len()
-    if discoveredPeers.isOk:
+    if discoveredPeers.isOk():
       for dp in discoveredPeers.get():
-        if dp.enr.isSome() and not px.enrCache.contains(dp.enr.get()):
-          px.enrCache.add(dp.enr.get())
+        if dp.enr.isSome() and not wpx.enrCache.contains(dp.enr.get()):
+          wpx.enrCache.add(dp.enr.get())
 
-    if px.enrCache.len() >= MaxCacheSize:
-      px.cleanCache()
+    if wpx.enrCache.len() >= MaxCacheSize:
+      wpx.cleanCache()
 
     ## This loop "competes" with the loop in wakunode2
     ## For the purpose of collecting px peers, 30 sec intervals should be enough
     await sleepAsync(30.seconds)
 
-proc getEnrsFromCache(px: WakuPeerExchange, numPeers: uint64): seq[enr.Record] {.gcsafe.} =
+proc getEnrsFromCache(wpx: WakuPeerExchange, numPeers: uint64): seq[enr.Record] {.gcsafe.} =
   randomize()
-  if px.enrCache.len() == 0:
+  if wpx.enrCache.len() == 0:
     debug "peer exchange ENR cache is empty"
     return @[]
-  for i in 0..<min(numPeers, px.enrCache.len().uint64()):
-    let ri = rand(0..<px.enrCache.len())
-    result.add(px.enrCache[ri])
-
-proc initProtocolHandler*(px: WakuPeerExchange) =
+  for i in 0..<min(numPeers, wpx.enrCache.len().uint64()):
+    let ri = rand(0..<wpx.enrCache.len())
+    result.add(wpx.enrCache[ri])
 
+proc initProtocolHandler(wpx: WakuPeerExchange) =
   proc handler(conn: Connection, proto: string) {.async, gcsafe, closure.} =
-    let message = await conn.readLp(MaxRpcSize.int)
+    let buff = await conn.readLp(MaxRpcSize.int)
 
-    let res = PeerExchangeRpc.init(message)
+    let res = PeerExchangeRpc.init(buff)
     if res.isErr():
       waku_px_errors.inc(labelValues = [decodeRpcFailure])
       return
@@ -166,8 +164,8 @@ proc initProtocolHandler*(px: WakuPeerExchange) =
     # handle peer exchange request
     if rpc.request != PeerExchangeRequest():
       trace "peer exchange request received"
-      let enrs = px.getEnrsFromCache(rpc.request.numPeers)
-      discard await px.respond(enrs, conn.peerId)
+      let enrs = wpx.getEnrsFromCache(rpc.request.numPeers)
+      discard await wpx.respond(enrs, conn.peerId)
       waku_px_peers_sent.inc(enrs.len().int64())
 
     # handle peer exchange response
@@ -182,28 +180,22 @@ proc initProtocolHandler*(px: WakuPeerExchange) =
         remotePeerInfoList.add(record.toRemotePeerInfo().get)
 
       let newPeers = remotePeerInfoList.filterIt(
-        not px.peerManager.switch.isConnected(it.peerId))
+        not wpx.peerManager.switch.isConnected(it.peerId))
 
       if newPeers.len() > 0:
         waku_px_peers_received_unknown.inc(newPeers.len().int64())
         debug "Connecting to newly discovered peers", count=newPeers.len()
-        await px.peerManager.connectToNodes(newPeers, WakuRelayCodec, source = "peer exchange")
+        await wpx.peerManager.connectToNodes(newPeers, WakuRelayCodec, source = "peer exchange")
 
-  px.handler = handler
-  px.codec = WakuPeerExchangeCodec
+  wpx.handler = handler
+  wpx.codec = WakuPeerExchangeCodec
 
-proc init*(T: type WakuPeerExchange,
-            peerManager: PeerManager,
-            wakuDiscv5: Option[WakuDiscoveryV5] = none(WakuDiscoveryV5)
-          ): T =
-  let px = WakuPeerExchange(
+proc new*(T: type WakuPeerExchange,
+          peerManager: PeerManager,
+          wakuDiscv5: Option[WakuDiscoveryV5] = none(WakuDiscoveryV5)): T =
+  let wpx = WakuPeerExchange(
     peerManager: peerManager,
     wakuDiscv5: wakuDiscv5
   )
-  px.initProtocolHandler()
-  return px
-
-proc setPeer*(wpx: WakuPeerExchange, peer: RemotePeerInfo) =
-  wpx.peerManager.addPeer(peer, WakuPeerExchangeCodec)
-  waku_px_peers.inc()
-
+  wpx.initProtocolHandler()
+  return wpx